app-misc/ca-certificates: Account for certs missing newlines

Concatenating certificates missing newlines naively with cat results in broken
bundle. Fix the issue by using a sed expression that appends a trailing newline
after the lastline if it is missing.

Issue: flatcar/Flatcar#1601
Signed-off-by: Jeremi Piotrowski <[email protected]>

Author: jepio

sdk_container/src/third_party/coreos-overlay/app-misc/ca-certificates/ca-certificates-3.108.ebuild renamed to sdk_container/src/third_party/coreos-overlay/app-misc/ca-certificates/ca-certificates-3.108-r1.ebuild

@@ -32,7 +32,10 @@ if [[ ! -e "${CERTBUNDLE}" || "${CERTSDIR}" -nt "${CERTBUNDLE}" ]]; then
     trap "rm -f '${CERTSDIR}/${TEMPBUNDLE}'" EXIT
 
     # Use .0 instead of .pem to pull in only what c_rehash validated
-    cat "${CERTSDIR}"/*.[0-9] > "${TEMPBUNDLE}"
+    for f in "${CERTSDIR}"/*.[0-9]; do
+        sed '$a\' "${f}"
+    done > "${TEMPBUNDLE}"
+
     chmod 644 "${TEMPBUNDLE}"
     mv -f "${TEMPBUNDLE}" "${CERTBUNDLE}"
     trap - EXIT